A two stroke will run with bad rings and a good piston. It will NOT run with a bad piston no matter how good the rings are! It goes against what you know for four strokes doesn't it?
Also be carefully when ordering either as the 030 had the 44mm rings and piston or 45mm rings and piston. Doesn't make a lot sense as they only list the 45mm cylinder.
There are a set of caber rings on eBay, there's also a brand new oem piston kit for $85. You can also buy rings for another saw of any brand as long as their size matches.